This invention concerns a transducer assembly adapted to be worn by a person using an auxiliary apparatus including a sound transmitting earpiece, for the purpose of picking up sound signals received from such an earpiece, in addition to the speech of the wearer, and/or for transmitting to the wearer sound signals to supplement those generated by the earpiece.
The auxiliary apparatus comprising the earpiece may, for example, be a mobile telephone, cordless telephone or telephone handset.
It is an object of the invention to provide such a transducer assembly that is less susceptible to electrical interference generated by the apparatus comprising the earpiece.
For example, it has been found that attempts to use a microphone near a mobile telephone or cordless telephone, for the purposes of picking up and recording speech signals together with incoming signals from the mobile telephone, can be defeated by the large amounts of electrical interference generated by such devices. This interference sometimes can be an annoyance up to 0.5 meters from microphone to source and can be particularly troublesome if the microphone transducer is actually or almost in contact with the body of the telephone without some sort of electromagnetic screening between them.
In accordance with the invention there is provided a transducer assembly comprising a sound transmitting element adapted to be worn in the ear, a transducer means for converting sound to electrical signals and/or vice versa, and an elongate hollow conduit extending between said sound transmitting element and said transducer, the arrangement being such that, in use, with the sound transmitting element located between the ear of the wearer and an external earpiece, the hollow conduit serves to provide coupling between the sound transmitting element and the transducer located at a point remote from the earpiece. An assembly in accordance with the invention allows a transducer to be located remotely from an apparatus such as a mobile telephone, so that it is free of electrical interference, whilst being acoustically coupled to the space between an earpiece of the apparatus and the ear of the wearer in a surprisingly simple manner. The sound transmitting element to be located between the earpiece and the ear may, for example, comprise a ball-shaped portion of synthetic plastic foam material and the conduit means may be provided by a simple hollow tube of flexible material engaging within the foam material at a point offset from the centre thereof. very surprisingly a tube having a bore of only approximately 1-2 mm in diameter will provide effective acoustic coupling to the transducer over a distance of 0.25-1 meter. The sound transmitting element may alternatively comprise a moulded element of more rigid material shaped to fit the ear and incorporating a sound transmitting aperture providing coupling between the ear and an external earpiece, with a transverse bore enabling coupling between the said aperture and a flexible tube providing the required conduit.
The invention is illustrated by way of example in the accompanying drawings, in which: